Interchangeable contact connector and method of construction

Abstract: A connector is provided of the type which has replaceable contact assemblies, including a contact assembly (14), with a circuit component (70) thereon that has three terminals (72, 74, 76), one (72) connected to the body (54) of the contact assembly, a second (74) connected to a first clip (80) which engages a ground plane (50) of the connector, and a third terminal (76) which engages a second clip (82). A circuit board (52) is mounted in the connector in a plane normal to the axes (31) of the contact assemblies, the circuit board having holes (110) that each receive a different contact assembly. A hole that receives the component contact assembly, is plated and holds a spring clip device (120) that has fingers (124) that bear against the second clip.

Description: This invention relates to electrical connectors which incorporate a three terminal electrical component. One type of connector includes contact assemblies with diodes and/or filter components. Such contact assemblies divert to ground any high voltage pulses, and can filter out unwanted frequencies. If a diode is destroyed when diverting a high energy pulse to ground, the contact assembly can be removed and another installed by sliding it until a clip on the contact assembly wipes against a ground plane mounted in the insulator assembly. The replaceable contact assemblies connect to circuitry which may include circuit boards holding multi-terminal components such as transistors and integrated circuits. Due to the easy replaceability of contact assemblies, it would be desirable if components more complex than diodes could be readily replaced. United States of America patent Number US-A-5164873 (Krantz) describes a connector having contacts each having two circuit components each having two terminals. The specification does not suggest any means for employing a three terminal device which allows the incorporation of transistors with the inherent advantages of their many capabilities such as amplification and digital to analogue conversion. The present invention seeks to provide a connector incorporating a three terminal device. According to one aspect of the invention there is provided a connector comprising a replaceable contact assembly, characterised in that the contact assembly is provided with a circuit component thereon that has three terminals, one of which terminals is connected to the body of the contact assembly, a second of which terminals is connected to a first clip which engages a ground plane of the connector, and a third of which terminals engages a second clip. According to another aspect of the invention, There is provided a method of constructing a connector which includes installing a plurality of insulators in a shell that has an axis, with each insulator having faces lying primarily in planes normal to the axis, characterised in that the steps of locating a sheet-like ground plane between a first pair of the insulators, wherein the ground plane and insulators have a plurality of holes forming a plurality of passages, constructing a plate-like circuit board and locating it between a second pair of insulators, with the circuit board having a plurality of holes each aligned with one of the passages including a first hole aligned with a first of the passages, and with a first trace lying on the board and a board clip device connected to the trace and lying at the first circuit board hole; forming a plurality of contact assemblies and installing each in a different one of the passages, including forming a component contact assembly with a conductive body having a middle, and mounting a circuit component on the body middle with the component having a first terminal connected to the body middle, and with the component having second and third terminals, the step of forming a component contact assembly including installing first and second clips that each have fingers and a band, the fingers of the first and second clips respectively engaging the second and third terminals and the bands each extending around the body middle, and installing a potting material within the bands and around the body middle the step of installing includes inserting the component contact assembly into the first passage until the first and second clips respectively electrically couple to the ground plane and to the circuit board trace. In order that the invention and its various other preferred features may be understood more easily, some embodiments thereof will now be described, by way of example only, with reference to the drawings, in which:- Figure 1 is a front elevation view of a connector constructed in accordance with the invention, Figure 2 is an isometric view of a three component contact assembly of the connector of Figure 1, with the clips shown in section, Figure 3 is a partial sectional view of the three terminal contact assembly of Figure 2, showing it fully installed in the connector of Figure 1, Figure 4 is a partial sectional view of a signal/bias contact assembly, showing it fully installed in the connector, Figure 5 is a partial sectional view showing a ground contact assembly fully installed in the connector, Figure 6 is a sectional view taken on the line 6 - 6 of Fig. 1, Figure 7 is an isometric view of a spring clip device of the connector of Figure 6, Figure 8 is a simplified schematic diagram of part of the circuitry of the connector of Figure 6, Figure 9 is a partial sectional view of a double grounding contact assembly constructed in accordance with the present invention, Figure 6 illustrates a connector 10 of the present invention, which includes a housing 12 and a plurality of contact assemblies 14 - 18 installed therein. The housing includes a metal shell 20 and an insulator assembly 22 within the shell. The insulator assembly includes four plate-like insulators 24, 25, 26 and 28 with their faces lying in planes such as 30 that extend normal to the axes 31 - 33 of the contact assemblies. It is noted that the axis 32 of one of the contact assemblies is coincident with the axis of the connector and of its shell. Each of the insulators 24 - 28 has a plurality of holes such as 34, 35, 36 and 38 with the holes being aligned and forming passages 40 that each receives one of the contact assemblies. It is noted that the particular connector shown includes a plurality of tail contacts 42 that are each fixed in place in a quantity 44 of potting materials such as epoxy, and that each have forward ends engaged with the rearward end of a corresponding contact assembly. The connector also includes a ground plane 50 of conductive material such as a copper alloy, for grounding some of the contact assemblies. The connector also includes a circuit board 52 with surfaces lying parallel to plane 30, whose function will be described below. Figure 2 shows details of the first contact assembly 14. It includes a conductive body 54 that has forward and rearward end portions 60, 62 and a middle 64 between them. The middle forms a platform 66 which holds a three terminal circuit component 70. The component can be a transistor, voltage regulator, or other device. The circuit component has a first terminal 72 which contacts the middle 64 of the contact body, and has second and third terminals 74, 76. Connection is made to the second and third terminals by first and second clips 80, 82. The first clip has a band part 84 lying forwardly, in direction F, of most of the component 70. The first clip also has a finger 86 extending largely rearwardly from the band part, in direction R, and also radially inwardly towards the contact axis 31, with the finger connected to the component second terminal 74 as by soldering. The second clip 82 is similarly constructed, but its band part 90 lies rearwardly of most of the circuit component 70. A finger 92 of the second clip extends forwardly and with a radially inward directional component from the band and connects to the third terminal 76 of the circuit component. For clarity, Figure 2 shows the clips 80, 82 in section, but does not show potting material which protects the circuit component and stabilizes the positions of the clips. Figure 3 shows the middle of the component contact assembly 14, fully installed in the connector 10. This figure shows a quantity 100 of dielectric material which isolates the clip band parts from the contact body 54. The dielectric material 100 is a potting material which surrounds the three-terminal circuit component 70 and which lies within the band parts 84, 90 of the clips 80, 82. The ground plane 50 has a hole 102 and has tines 104 at the hole that engage the band part 84 of the first clip, to thereby ground the second terminal 74 of the circuit component. The circuit board 52 has a plated-through hole 110, with the plating including a portion 112 that lies on a forward surface 114 of the board as well as on the opposite rearward surface 116, with the rearward part of the plating merging with a conductive trace 118. The circuit board includes a spring clip device 120 that connects the plating part 112 and trace 118, to the second clip 82, and therefore to the third terminal 76 of the circuit component. The spring clip device has a largely cylindrical part 122 that is fastened to the circuit board plating as by soldering thereto. A plurality of fingers 124 extends rearwardly from the cylindrical part and slightly towards the contact axis 31, to engage the band part 90 of the second clip. Thus, when the component contact assembly 14 is installed, by moving it rearwardly into the passage 40, the band parts 84, 90 of its first and second clips make electrical connection respectively with the ground plane 50 and circuit board trace 118. The contact assembly can be removed in a forward direction F, and its clip band parts then move slidably out of contact with the ground plane tines and circuit board clip device fingers. Figure 8 is a simplified schematic diagram showing the interconnection of the contact assemblies. The component contact assembly is represented at 14, with the conductive body 54 shown connected to the first terminal 72 of the three terminal circuit component 70. The finger 104 of the ground plane 50 connects the second terminal 74 to ground. The spring clip device 120 connects the third terminal 76 to the circuit board trace 118. The trace 118 connects, either directly or through a small circuit component (e.g. resistor, capacitor, diode) to another circuit board trace portion 118A. The second trace portion 118A connects to a second spring clip device 130 that connects to the conductive body 132 of the bias/signal contact 16. Thus, the signal on the body 54 of the component contact assembly 14 is modified by the circuit component 70, and the modified signal is delivered (with possible additional modification) carries the modified signal to circuitry outside the connector. Figure 4 shows mechanical details of the bias/signal contact assembly 16. This contact assembly includes a conductive body 132 with a board connected part 134 having a substantially cylindrical outer surface 136. The second spring clip device 130 is of the same construction as the earlier described first one 120. The fingers 124 of the second clip device engage the cylindrical surface 136 of the conductive body 132. In this way, the bias/signal contact assembly 16 is electrically coupled to the third terminal 76 of the three terminal circuit device on the component contact assembly 14. In order to prevent the body 132 of the bias/signal contact assembly from engaging the tines 104 of the ground plane 50, a quantity 140 of potting material is provided around a reduced diameter, or narrowed, part 142 of the conductive body 132. The outside diameter of the potting material 140 is of substantially the same outside diameter as the band part of the first clip 80 on the component contact assembly 14. This facilitates insertion of any of the contact assemblies into any of the passages without difficulty. It also enables the ground plane fingers to stabilize the position of every contact assembly. Such interchangeability enables the customer who buys the connector and selected contact assemblies, to be assured that any contact assembly can be installed in any of the passages. It may be noted that the bias/signal contact can be used to transmit a constant voltage (bias), as well as a signal that rapidly changes in voltage. However, the bias/signal contact assembly is usually used to transmit a signal, and then can be referred to as a signal contact assembly. Figure 5 illustrates the third contact assembly 18 which is a ground contact assembly. The ground contact assembly 18 has a conductive body 150 that is connected to ground at either its front or rear portion 60, 62. The purpose of the ground contact assembly 18 is to maintain the ground plane 50 at ground potential, as by connection indicated at 152 to ground. The ground body 150 has a cylindrical outer surface at 154 adjacent to the ground plane 50 to contact the tines 104 of the ground plane lying at the corresponding hole therein. The body 150 has a reduced diameter portion at 156 which is surrounded by a third quantity 160 of potting material such as epoxy, to provide the same outside diameter as the middle of the other contact assemblies. Thus a third spring contact device 164 does not electrically connect to the ground contact assembly. Referring again to Figure 6, it can be seen that the connector includes a retainer 170 in each hole 34 of the insulator 24, to retain the corresponding contact. A front release tool can be inserted through a soft rubber seal 172 to expand the fingers of the retainer and allow the corresponding contact assembly to be pulled out. During such pull out, the contact assembly slides across the tines of the ground plane 50 and the fingers of the spring clip devices that are mounted on the circuit board. It should be noted that it is possible for the ground plane 50 to be grounded by providing fingers, indicated in phantom lines at 174, at its periphery that bear against the inside wall of the shell 20. However, this may require plating of the inside surface of the shell 20 to assure good contact of the ground plane therewith. It is also possible to provide a double grounding contact assembly 180 shown in Figure 9, instead of the grounding contact assembly 18 shown in Figure 5. The contact assembly 180 in Figure 9 is intended to contact the ground plane 50, and also a spring clip assembly 182 which is connected to a ground plane of the circuit board 52. Thus, the invention provides a component contact assembly that can hold a circuit component with three terminals, and which provides means for connection to each of the terminals. The component contact assembly includes first and second clips that are respectively connected to the second and third terminals of the component, with each clip having a largely cylindrical exposed band, with a first band connected to a ground plane of the connector. The connector includes a circuit board whose surfaces extend in a plane normal to the axes of the contact assemblies. The circuit board carries a spring clip device in each of its holes, the clip device having fingers that engage the band of the second clip on the component contact assembly. The circuit board has traces that can connect to a bias/signal contact assembly to thereby connect the third terminal of the component on the component contact assembly, to circuitry outside the connector.

Claims: A connector (10) comprising a replaceable contact assembly (14), provided with a circuit component (70) thereon, characterised in that the circuit component (70) has three terminals (72, 74, 76), one of which terminals (72) is connected to the body (54) of the contact assembly, a second of which terminals (74) is connected to a first clip (80) which engages a ground plane (50) of the connector, and a third of which terminals (76) engages a second clip (82). A connector (10) as claimed in claim 1, further comprising a housing (12) with an insulator assembly (22) forming a plurality of passages (40), having a ground plane (50) mounted on the insulator assembly, having a plurality of contact assemblies (14,16,18) each mounted in one of the passages, and a circuit board (52) mounted in the housing, having a first conductive trace (118) electrically coupled to the second clip (82) of the contact assemblies. A connector (10) as claimed in claim 2, wherein the circuit board (52) has a plurality of holes each aligned with a corresponding one of the passages (40), including a first hole, the first trace plating (118) at least a region on the board (52) which surrounds the first hole, a spring device (120) which lies in the first hole of the circuit board (52) and which is electrically connected to the first trace (118), the spring device (120) having a plurality of spring fingers (124) which press against the second clip (82), to thereby electrically couple the component third terminal (76) to the first circuit board trace (118). A connector (10) as claimed in claims 2 or 3, wherein the plurality of contact assemblies (14-18) includes a bias/signal contact assembly (16) lying in a second of the passages (40), the bias/signal contact assembly (16) having an electrically conductive body (132) which includes a board-connected part (134) having a substantially cylindrical outer surface (136) and lying adjacent to a second of the holes in the circuit board (52), and the circuit board (52) having a second trace coupled to the first trace (118) and connected to the cylindrical outer surface (136). A connector (10) as claimed in claim 4, wherein the body of the bias/signal contact assembly (132) has a narrowed part (142) adjacent to the ground plane (50), and including a quantity of insulative potting material (140) lying about the narrowed part (142) and forming a substantially cylindrical outer surface (136). A connector (10) as claimed in any of claims 2 to 5, wherein the plurality of contact assemblies (14-18) includes a ground contact assembly (18) lying in a third of the passages (40), the ground contact assembly (18) having an electrically conductive body (150) connected to the ground plane (50) means for maintaining a ground potential on the body of the ground contact assembly (150) independently of the ground plane (50), to thereby electrically ground the ground plane (50) by means of the ground contact assembly (18). A connector (10) as claimed in any of the previous claims, wherein the first clip (80) comprises a band part (84) lying forward of a portion of the component and having a finger (86) extending partially rearwardly from the band part and connected to the component second terminal (74), and the second clip (82) comprises a band part (90) lying rearward of a portion of the component and having a finger (92) extending largely forwardly from the second clip band part and connected to the component third terminal (76), and a quantity of dielectric material (100) which lies within said band portions of said first (80) and second clips (82) and isolates said band portions from said contact body. A connection assembly including a connector (10) as claimed in claim 7, the connection assembly having a shell (20) and an insulator assembly (22) mounted in the shell (20), the insulator assembly (22) having a plurality of passages, and the connector (10) with the circuit component (70), clips (80,82) and dielectric material (100) lying in a first of the passages (40), a ground plane (50) lying within the shell (20) and having a plurality of holes (34-38) each aligned with one of the passages (40), the first (80) and second (82) clips forming ground and board clips respectively and the ground plane (50) coupled to the ground clip (80), a circuit board (52) mounted in the shell (20) and having a plurality of holes including a first hole aligned with the first passage (40) in said insulator assembly (22), the circuit board (52) having a plurality of conductive traces, including a first trace (118) electrically coupled to the board clip (82). A connection assembly as claimed in claim 8, including a bias/signal contact assembly (16) which lies in a second of the passages (40), the bias/signal contact assembly (16) including a conductive bias/signal body (132) having forward and rearward end parts and a middle, the bias/signal body (132) including a cylindrical portion (136) having an outside diameter substantially equal to the board clip (82) and electrically coupled to the first trace (118) on the circuit board (52), a second quantity of dielectric material (140) surrounding a portion of the bias/signal middle which lies substantially within a corresponding one of the holes in the ground plane (50). A connection assembly as claimed in claims 8 or 9, including a ground contact assembly (18) which lies in a third of the passages, the ground contact assembly (18) including a conductive ground body (150) having forward and rearward end parts and a middle, the body (150) including a largely cylindrical portion (154) having an outside diameter substantially equal to that of the ground clip (80) and electrically coupled to the ground plane (50), a third quantity of dielectric material (156) surrounding a portion of the ground body middle which lies within a corresponding one of the holes in the circuit board (52). A connector (10) as claimed in any of claims 2 to 6, wherein the circuit board (52) is mounted in the housing (12), the board (52) lies in a plane (30) that is normal to the passages (40) and has a plurality of holes each aligned with one of the passages (40), which board has a first conductive trace (118) coupled to the clip (82) at one of the board holes. A connector (10) as claimed in claim 11, wherein the ground plane (50) lies in the insulator assembly (22) and extends substantially in a plane (30) normal to the lengths of the passages (40), which ground plane (50) has a plurality of holes each aligned with one of the passages (40). A connector (10) as claimed in claims 11 or 12, wherein a second of the contact assemblies is a bias/signal contact assembly (16) that lies in a second hole of the circuit board (52) and which is coupled to the first conductive trace (118). A method of constructing a connector (10) which includes installing a plurality of insulators (24-28) in a shell (20) that has an axis, with each insulator having faces lying primarily in planes normal to the axis, characterised in that the steps of locating a sheet-like ground plane (50) between a first pair of the insulators, wherein the ground plane (50) and insulators have a plurality of holes (34-38) forming a plurality of passages (40), constructing a plate-like circuit board (52) and locating it between a second pair of insulators, with the circuit board (52) having a plurality of holes each aligned with one of the passages (40) including a first hole aligned with a first of the passages, and with a first trace (118) lying on the board (52) and a board clip device (82) connected to the trace (118) and lying at the first circuit board hole; forming a plurality of contact assemblies (14-18) and installing each in a different one of the passages, including forming a component contact assembly (10) with a conductive body having a middle, and mounting a circuit component (70) on the body middle with the component (70) having a first terminal (72) connected to the body middle, and with the component having second (74) and third terminals (76), the step of forming a component contact assembly including installing first (80) and second (82) clips that each have fingers (86,92) and a band (84,90), the fingers (86,92) of the first (80) and second (82) clips respectively engaging the second (74) and third (76) terminals and the bands (84,90) each extending around the body middle, and installing a potting material (100) within the bands (84,90) and around the body middle the step of installing includes inserting the component contact assembly into the first passage until the first (80) and second (82) clips respectively electrically couple to the ground plane (50) and to the circuit board trace (118). A method as claimed in claim 14, wherein the step of constructing the board (52) includes plating the first hole by a plating that merges with the first trace (118), and installing a spring clip device (120) in the plated hole and soldering it to the plating (112), wherein the clip device (120) has a plurality of spring fingers (124) extending beyond the faces of the board (114,116), the step of installing the component contact (10) includes sliding it into the first passage until the second clip (82) wipes against the spring fingers (124) of the spring clip device (120).

Inventors: PAULUS ERIC JAMES, PAULUS, ERIC JAMES
Applicants: ITT, ITT INDUSTRIES, INC.
Application year: 1994
Main classification: H01R13
IPC codes: H01R13